Magnet assembly

ABSTRACT

A magnet assembly is provided including a housing having a first end and a second end. A magnet is placed within a recess formed in the first end of the housing and a spring is positioned in at least a portion of the second end of the housing. A method of mounting a magnet assembly in a tool is provided. The method includes providing a magnet assembly including a housing having a recess formed in a first end of the housing and a spring positioned in a second end of the housing. The method further includes placing the magnet assembly into an opening defined in a tool and placing a magnet into the recess, and pressing the magnet against the spring to position the magnet within the tool.

This application is a divisional of U.S. patent application Ser. No.11/023,973, filed Dec. 23, 2004, the disclosure of the above applicationis incorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The present invention relates to magnets. In particular, the presentinvention relates to a magnet including a housing for positioning themagnet within a tool.

2. Background Information

Many kinds of tools are known that incorporate a magnet or a magneticportion to facilitate the attachment of the tool to a metal object. Forexample, tools may be magnetized in order to hold the tools against ametal storage rack or against a metal work surface.

Some spirit level tools include a magnet to hold the level against apipe or other metal surface that needs to be leveled. When a magnet isused on the measuring surface, the magnet must be calibrated to be levelwith the leveling surface. Commonly, strip or bar magnets are used alonga measuring surface of the level, held in place by another bar oradhesive. Alternatively, the strip or bar magnets may be held in placewith plastic brackets that snap into place in the measuring surfacewhich then must be calibrated and secured into position. Thiscalibration of structures such as snap-in brackets or bars can be costlyand time-consuming.

Therefore, it is an object of the present invention to provide a magnetassembly that is easily and inexpensively mounted in a tool and whichmay be easily calibrated using a biasing spring when the magnet assemblyis inserted into the tool.

BRIEF SUMMARY

In order to alleviate one or more shortcomings of the prior art, amagnet assembly and a method for mounting a magnet assembly in a toolare provided herein.

In one aspect of the present invention, a magnet assembly for mountinginto a tool is provided. The magnet assembly includes a housing having afirst end and a second end. A magnet is placed within a recess formed inthe first end of the housing and a spring is positioned in at least aportion of the second end of the housing. The spring biases the magnetrelative to at least a portion of the tool.

In another aspect of the present invention, a method of placing a magnetassembly in a tool is provided. The method includes providing a magnetassembly including a housing having a recess formed in a first end ofthe housing and a spring positioned in a second end of the housing. Themethod further includes placing the magnet assembly in an openingdefined in a tool and placing a magnet into the recess and pressing themagnet against the spring into position within the tool.

In another aspect of the present invention, a device is providedincluding a level having a measuring surface, an opening defined intothe measuring surface and a magnet assembly for placement at leastpartially within the opening. The magnet assembly includes a housinghaving a first end and a second end, a magnet placed within a recessformed in the first end of the housing and a spring positioned in atleast a portion of the second end of the housing. The spring biases themagnet relative to the level.

In another aspect of the present invention, a magnet assembly formounting into a tool having a level surface is provided. The magnetassembly includes an expandable housing having a first end including anopening defined therein and a second end. The magnet assembly furtherincludes a magnet placed within the opening in a position for alignmentof the magnet with the level surface. The opening is adapted to expandfor reception of said magnet and the housing frictionally engages themagnet and the tool to retain the magnet in the tool.

In yet another aspect of the present invention, a method is provided forplacing a magnet assembly in a tool. The method includes providing amagnet assembly housing having a housing opening defined therein,placing the housing in an opening defined in the tool and placing themagnet in the housing opening and pressing the magnet into alignmentwith a level surface of tool. The tool opening is sized to frictionallyreceive the housing.

Advantages of the present invention will become more apparent to thoseskilled in the art from the following description of the preferredembodiment of the invention which has been shown and described by way ofillustration. As will be realized, the invention is capable of other anddifferent embodiments, and its details are capable of modification ofvarious respects. Accordingly, the drawings and description are to beregarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a magnet assembly in accordancewith the present invention;

FIG. 2 is side elevational view of a first portion of the housing of themagnet assembly shown in FIG. 1;

FIG. 3 is a perspective view of the first portion of the housing shownin FIG. 2;

FIG. 4 is a side elevational view of a second portion of the housing ofthe magnet assembly shown in FIG. 1:

FIG. 5 is a bottom view of a level including the magnet assembly shownin FIG. 1;

FIG. 6 is an alternative embodiment of a magnet assembly in accordancewith the present invention;

FIG. 7 is an alternative embodiment of a magnet assembly in accordancewith the present invention; and

FIG. 8 is a sectional view of the embodiment shown in FIG. 7.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

A preferred embodiment of the magnet assembly 10 of the presentinvention is shown in FIG. 1. The magnet assembly 10 includes a housing20 having a first portion 22 and a second portion 24, a spring 26 and amagnet 28.

The first portion 22 of the housing 20 of the preferred embodiment isshown in FIG. 2. The outer surface 32 of the first portion 22 isgenerally cylindrically shaped. Although the outer surface 32 of thefirst portion 22 is shown as being cylindrically shaped, those skilledin the art will readily understand that the outer surface 32 may bealternatively shaped. For example, the outer surface 32 may beelliptical, cuboidal, or any shape adapted to fit within a tool such asa level. In the preferred embodiment, the outer surface 32 includes aproximal section 34 and a reduced diameter distal section 36. The firstportion 22 includes an interior bore 38 defined inwardly from an opening40 in a proximal end 42 through to the distal end 36.

A first recess 44 is formed beginning at the opening 40 and the firstrecess 44 is sized to receive the magnet 28 so that a top surface 46 ofthe magnet 28 may be calibrated to be level with a tool into which themagnet assembly 10 has been mounted. (Described in more detail below.)The magnet 28 may be any type of magnet known to one of skill in theart. The magnet 28 is shaped to fit closely within the first recess 44and the top surface 46 of the magnet 28 is preferably coplanar inrelation to an outer surface of the tool into which the magnet assembly10 is inserted. In addition, a second recess 52 formed in the distal end36 includes an opening 53 sized to receive a first end 57 of the spring26.

As shown in FIG. 3, the proximal end 42 of the first section 22 mayfurther include a flange 54 extending radially outwardly from theproximal section 34. In a preferred embodiment, the exterior 56 of theflange 54 forms a square-shaped outline. One of skill in the art willrecognize that the flange 54 may be any shape, including but not limitedto circular, elliptical, rectangular, and triangular.

The second portion 24 of the housing 20 of the preferred embodiment isshown in FIG. 4. The second portion 24 is shaped in complimentaryfashion to telescopically mount with the first portion 22 of the housing20. The second portion 24 and the first portion 22 move relative to eachother. When the first portion 22 of the housing 20 is cylindricallyshaped, the second portion 24 also includes a cylindrically shaped outersurface 58. The outer surface 58 is formed from a flange 60 upstandingfrom a first end 62 of the second portion 24. A projection 64 extendsaxially from the first end 62 interior to the flange 60. The projection64 is also shaped to fit with the interior of the bore 38 of the firstportion 22. Any shape for the projection 64 may be used to fit with thecorresponding shape of the interior bore 38. In a preferred embodiment,the projection 64 is cylindrically shaped and includes an interior bore68 that extends through the second portion 24. An annular space 70 isformed between the flange 60 and the projection 64 and includes asurface 71 at the bottom of the space 70. A second end 74 of the spring26 contacts the surface 71 in the preferred magnet assembly 10. Thesecond portion 24 may further include a recess 72 formed in the firstend 62 of the second portion 24. As shown in FIG. 4, the interior bore68 opens into the recess 72. The recess 72 may be any shape, includingcylindrical as shown. The housing 20 may be made from any material knownto one of skill in the art, preferably ABS plastic.

The spring 26 of a preferred embodiment is shown in FIG. 1 as a helicalcoil. Alternatively, the spring 26 may be any type of spring known toone of skill in the art, including an elastomeric structure such as ano-ring. The spring may be formed from metal, plastic, or any suitablematerial. As shown, the spring 26 surrounds a portion of the projection64 of the second portion 24 and abuts the surface 71 at the second end74. The first end 57 of the spring 26 also fits in the opening 53 of therecess 52 and in the first portion 22. Together, the spring 26 and thedistal section 36 of the first portion 22 slidably telescope into thespace 70 between the projection 64 and the flange 60.

Installation and alignment of the magnet assembly 10 is as follows andis given with reference to placement of the magnet assembly 10 within aleveling tool 80. One of skill in the art, however, will readilyrecognize that the magnet assembly 10 may be placed in any device inwhich a magnet may be used. In the illustrated magnet assembly 10 inFIG. 1, the housing 20 is shown assembled with the spring 26 placedpartially surrounding the projection 64 of the second portion 24 andabutting the surface 71 of the second portion 24. The first portion 22is placed over the second portion 24 so that the spring 26 and thedistal section 36 slidably mount interior to the flange 60. The firstend 57 the spring 26 abuts the first portion 22 and the spring 26 iscompressible between the first portion 22 and the second portion 24. Thespring 26 biases the first portion 22 away from the second portion 24 inthis state.

During installation, adhesive may be added. In the preferred embodiment,adhesive is added to the housing 20 after the housing 20 is placed in atool. Alternatively, the adhesive may be added to the housing 20 priorto mounting the housing 20 in the tool.

In the preferred embodiment, the housing 20 assembled together with thespring 26 may be inserted into an opening 90 defined in the measuringsurface 92 of a spirit level tool extrusion 94, as shown in FIG. 5. Anadhesive, preferably a fluid adhesive, is supplied to the opening 90 andinto the housing 20. By way of example, an adhesive such as urethane orepoxy may be used. A preferred urethane is Loctite #U-09FL that may beobtained from Henkel Loctite Corporation, Rocky Hill, Conn. In thepreferred embodiment, the magnet 28 is inserted into the opening 40 inthe recess 44 of the first portion 22. One of skill in the art willrecognize that the magnet 28 may be placed in the opening 40 prior tothe addition of the adhesive. When the magnet 28 is mounted in theopening 40, at least a portion of the magnet 28 protrudes out of theopening 90 above the measuring surface 94 due to the biasing of thesecond portion 24 away from the first portion 22 by the spring 26. Thetop surface 46 of the magnet 28 may be aligned to be coplanar with themeasuring surface 92 of the level extrusion 94 by pressing the magnet 28against the spring 26. The flange 54 of the first portion 22 preferablyis used to position the magnet assembly 10 in the level extrusion 94 tohold the magnet assembly 10 in place below the measuring surface 92 andto hold the first portion 22 substantially perpendicular in the levelextrusion 94 with respect to the measuring surface 92. A plurality ofmagnet assemblies 10 may be inserted into the level extrusion 94, at anyposition on the measuring surface, and aligned as described.

In order to align the top surface 46 of the magnet 28 to be coplanarwith the measuring surface 92, the magnet 28 may be pressed intoposition against the spring 26 in the opening 90. When the magnet 28 isaligned to be coplanar with the measuring surface 92, the top surface 46is aligned with the measuring surface 92 by compressing the spring 26allowing rapid and easy alignment of the magnet 28. The spring 26 allowsfor easy correction of the alignment of the magnet 26 to make the magnetcoplanar with the measuring surface 92 by continually biasing the spring26 away from the leveling tool 80. For example, if the top surface 46 ofthe magnet 28 is pressed below the measuring surface 92 during thealigning procedure, the spring 26 biases the magnet 28 away from theleveling tool 80 and above the measuring surface 92 for easyrealignment. No additional tools or operator manipulation are necessaryto realign the top surface 46 of the magnet 28 with the measuringsurface 92 as would be required with the snap-in bracket, for example.

When the spring 26 is compressed, the first portion 22 and the secondportion 24 telescope inward toward each other. The inward telescopingmovement of the first portion 22 and the second portion 24 presses theadhesive into the housing 20, spreading the adhesive. The spring 26 maybe compressed until the top surface 46 of the magnet 28 is aligned to becoplanar with the measuring surface 92. A metal plate, not shown, may beplaced flush with the measuring surface 92 for alignment of the magnet28. The metal plate draws the magnet 28 to the plate, for example if themagnet 28 is recessed within the tool 80 and the metal plate holds themagnet 28 level with the measuring surface. Once the magnet 28 isaligned, the magnet assembly 10 is held in place in the level 80 untilthe adhesive hardens and the magnet assembly 10 is secured in positionwith the top surface 46 of the magnet 28 fixedly aligned with themeasuring surface 92. Preferably, the fixture time of the liquidadhesive is about 24 hours and the full cure time is about 72 hours. Oneof skill in the art will recognize that heat may be applied to shortenthe fixture and curing times. Of course, other liquid adhesives may beused having differing times to fix and cure the adhesive used to securethe magnet assembly 10 into place in the leveling tool 80.

Alternatively, adhesive may be placed in the housing 20 prior to placingthe housing 20 assembled with the spring 26 into the opening 90 of themeasuring surface 92. The housing 20 may be assembled with the spring 26and adhesive added to the housing 20 in the opening 40 of the firstrecess 44 of the first portion 22. The housing 20 and the spring 26 withthe adhesive added may be positioned in the opening 90. The magnet 28may be inserted into the opening 40 of the recess 44 and the top surface46 may be aligned to be coplanar with the measuring surface 92 asdescribed above. In the preferred embodiment of the present inventionhaving a housing 20 that includes a first portion 22 and a secondportion 24, contact surfaces are provided on the housing portions 22, 24providing a greater surface area for the adhesive to adhere to in orderto securely fix the magnet 28 into an aligned, coplanar position in thelevel 80. For example, a contact face 76 may be formed between anexterior surface 78 of the distal section 36 of the first portion 22 andan interior surface 79 of the flange 60 of the second portion 24. Therecess 72 in the second portion 24 further provides a surface area forthe adhesive to deposit and secure the second portion 24 in the levelextrusion 94.

Alternatively, the magnet assembly 10 may be secured in position in thelevel extrusion 94 with a high strength spring 26 that biases the flange54 of the first portion 22 against an interior surface 93 of the level90 to hold the magnet 28 in calibrated position with respect to themeasuring surface 92. In another alternative embodiment of the presentinvention, sonic welding may be used to secure the magnet 28 in analigned position with respect to the measuring surface 92 against thebias of the spring 26.

In an alternative embodiment shown in FIG. 6, a magnet assembly 100includes fewer components than the magnet assembly 10. The magnetassembly 100 includes a unitary housing 102, a spring 126 and a magnet128. An outer surface 110 of the housing 102 may be generallycylindrically shaped, although any shape may be used, as described abovefor the first portion 22 of the housing 20. The housing 102 may furtherinclude a flange 154 extending radially outward as described for thefirst portion of the housing 22. The housing 102 includes an interiorbore 138 defined inwardly from an opening 140 in a first end 142 to anopening 153 at a second end 160.

In a preferred embodiment of the housing 102, a first recess 144 isformed beginning at the opening 140 and the recess 144 is sized toreceive the magnet 128 so that a top surface 146 of the magnet 128 maybe calibrated to be level with a tool into which the magnet assembly 100has been inserted. A second recess 152 is formed in the second end 160of the housing 102. The recess 152 is sized to receive at least aportion of the spring 126. The spring 126 abuts the housing 102 andbiases the housing 102 away from a tool into which the magnet assembly100 is placed.

Installation and alignment of the magnet assembly 100 is as follows andis given with reference to placement of the magnet assembly 100 in aleveling tool 80 as shown in FIG. 5 and described for the magnetassembly 10. One of skill in the art will readily recognize that themagnet assembly 100 may be placed in any device in which a magnet may beused. The magnet assembly 100 shown in FIG. 6 may be placed into theopening 90 in the measuring surface 92 of the level extrusion 94. Asdescribed above for the magnet assembly 10, the magnet assembly 100 maybe placed in the opening 90 and an adhesive may be added to the opening90 and into the housing 102. The magnet 128 may be placed into theopening 140 in the first section 144. The top surface 146 of the magnet128 may be aligned to be coplanar with the measuring surface 92 bybiasing the magnet against the spring 126 until the top surface 146 isaligned with respect to the measuring surface 92 as described above andsecured in position once the adhesive has solidified.

Alternatively, adhesive may be placed in the housing 102 prior toplacing the housing 102 and the spring 126 into the opening 90 of themeasuring surface 92. As described above for the magnet assembly 10, thehousing 102 and the spring 126 of the magnet assembly 100 may then beplaced in the opening 90, and the top surface 146 of the magnet 128aligned and the magnet assembly 100 is held in place until the adhesivesolidifies. The magnet assembly 100 may also be aligned and held inposition with a high strength spring 126 or sonic welding as describedabove for the magnet assembly 10.

An alternative embodiment of a magnet assembly 200 is shown in FIGS. 7and 8. The magnet assembly 200 includes a housing 202 and a magnet 228.An outer surface 210 of the housing may be generally cylindricallyshaped, although any shape may be used as described above. The outersurface 210 may further include at least one flange 222 extendingradially outwardly from the housing 202. The housing 202 includes afirst end 242 defining an opening 238 therein for reception of themagnet 228. As shown in FIG. 7, the first end 242 may include aplurality of recesses 254 formed around the opening 238, extendingtoward the second end 260. Preferably, the first end 242 includes 4recesses 254 offset by about 90° around the periphery of the opening238, although any number of recesses 254 may be included. The recesses254 allow the opening 238 to expand when the magnet 228 is inserted intothe opening 238 as described below. The housing 202 may include anopening 262 defined in the second end 260 of the housing 202, as shownin FIG. 8. Preferably, the housing 202 is formed from a plasticmaterial, such as ABS plastic. However, any material known to one ofskill in the art may be used to form the housing 202.

Installation and alignment of the magnet assembly 200 is as follows andis given with reference to placement of the magnet assembly 200 in aleveling tool 80 as shown in FIG. 5. One of skill in the art willreadily recognize that the magnet assembly 200 may be placed in anydevice in which a magnet may be used. The housing 202 may be insertedinto the opening 90 defined in the measuring surface of the levelingtool 80. Preferably, the inner diameter 91 of the opening 90 is smallerthan the outer diameter 264 of the housing 202 to provide a friction fitof the housing 202 in the opening 90. The flanges 222 may provideadditional surfaces for engagement of the housing 202 with the opening90. The magnet 228 may be pressed into the opening 238 in the first end242 of the housing 202. Preferably the magnet 228 is pressed into theopening 238 of the housing 202 using about 400 pounds per square inch offorce to drive the magnet 228 into the smaller opening 238 of thehousing 202 and thereby secure the magnet 228 by frictional engagement.More preferably, installation of the magnet 228 by force aligns asurface 240 of the magnet 228 with the measuring surface 92, within amaximum of about 0.005 to 0.010 inches below the measuring surface 92 ofthe tool 80, most preferably, maximally about 0.007 inches below themeasuring surface 92. The recesses 254 allow the first end 242 todeflect outwardly as the magnet 228 is forcibly pressed into the opening238.

Alternatively, the magnet 228 may be held in the housing 202 by theaddition of an adhesive. The adhesive may be added to the opening 238before or after the housing 202 is inserted into the opening 90 of thetool 80 as described above. Adhesive may also be used to secure thehousing 202 in the opening 90 of the level 80.

Although the invention herein has been described in connection with apreferred embodiment thereof, it will be appreciated by those skilled inthe art that additions, modifications, substitutions, and deletions notspecifically described may be made without departing from the spirit andscope of the invention as defined in the appended claims. It istherefore intended that the foregoing detailed description be regardedas illustrative rather than limiting, and that it be understood that itis the following claims, including all equivalents, that are intended todefine the spirit and scope of this invention.

1. A method of mounting a magnet assembly in a leveling tool having a measuring surface comprising: a housing having a first end and a second end, and a magnet on the first end; placing said housing into an opening defined in measuring surface, said opening sized to receive said housing and a spring abutting the housing and received by said second end such that said housing is biased by said spring away from the housing; pressing said magnet against said spring to move said magnet toward the housing where said magnet is in an aligned position relative to said measuring surface; and permanently securing said magnet in said aligned position.
 2. A leveling tool comprising: a measuring surface; an opening defined in said measuring surface; a magnet assembly located at least partially within said opening, said magnet assembly comprising: a housing having a first end and a second end; a magnet secured to said first end; and a spring compressed between the second end and the tool; and means for permanently fixing said housing relative to said tool such that said spring cannot move said housing relative to said tool.
 3. The leveling tool of claim 2, wherein the magnet is secured in an opening in said first end.
 4. The leveling tool of claim 2, wherein a portion of the spring is received in second recess formed in the second end.
 5. The leveling tool of claim 2, wherein the means for permanently fixing comprises adhesive.
 6. The leveling tool of claim 2, where the means for permanently fixing comprises welding.
 7. The leveling tool of claim 2, wherein the means for permanently fixing comprises a high strength spring.
 8. The leveling tool of claim 2, wherein the means for permanently fixing comprises frictional engagement.
 9. The leveling tool of claim 2, wherein the housing is formed of plastic.
 10. The leveling tool of claim 2, wherein the first end includes a plurality of recesses that allow the opening to expand when a magnet is inserted into the opening. 